func bonAppetit(bill []int32, k int32, b int32) {
    bill[k] = 0
    var total int32
    for _,v := range bill {
            total += v
    }
    refund := total/2
    if refund == b {
        fmt.Println("Bon Appetit")
    } else {
        fmt.Println(b - refund)
    }
    
}